Chronology of Milestone Events in Particle Physics - NISHINA 1937
Chronology of Milestone Events in Particle Physics

NISHINA 1937

Nishina, Y.; Takeuchi, M.; Ichimiya, T.;
On the Nature of Cosmic-Ray Particles
Phys. Rev. 52 (1937) 1198;

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Motivation
Various authors have taken the view that cosmic-ray particles consist of two or more kinds of corpuscules. According to Compton and Bethe, and Auger the soft component near sea level is thus composed of electrons and the penetrating one of protons. Assuming the theory of showers by Bhabha and Heitler to be correct, we ought to be able to distinguish cosmic-ray electrons from protons, if they exist at all, by observing whether or not the particles suffer a large loss of energy and often produce showers on colliding with a lead plate of a suitable thickness.
We carried out such experiments with a lead bar 1.5 cm thick mounted in the middle of a Wilson chamber 40 cm in diameter, which is placed in a magnetic field of about 17,000 oersteds. The operation of the chamber is actuated by the coincidence of two Geiger-Müller tube counters mounted above the chamber, the distance between the counters being about 50 cm. (Extracted from the introductory part of the paper.).

Accelerator COSM Detectors CLOUD, CNTR

Related references
See also
A. H. Compton and H. A. Bethe, Nature 134 (1934) 734;
P. Auger, Jour. de Phys. 6 (1935) 226;
C. D. Anderson and S. H. Neddermeyer, Phys. Rev. 50 (1936) 268;
C. D. Anderson and S. H. Neddermeyer, Phys. Rev. 51 (1937) 884;
J. Clay, Physica 3 (1936) 338;
J. C. Street et al., Bull.Am.Phys.Soc. 12 (1937) 13;
J. Crussard and L. Leprince-Ringuet, Compt. Ren. 204 (1937) 240;
J. Crussard and L. Leprince-Ringuet, Jour. de Phys. 8 (1937) 215;
H. J. Bhabha and W. Heitler, Proc. Roy. Soc. A159 (1937) 432;
J. F. Carlson and J. R. Oppenheimer, Phys. Rev. 51 (1937) 220;
L. Leprince-Ringuet, Jour. de Phys. 7 (1936) 70;

Particles studied
  + ex, mass
  ex, mass

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